Hard Rock on abandoned mines

Mining has been around for more than 130 years in Western Australia, and scattered across the state – particularly in remote areas – remain a number of abandoned mine sites.

For more than a decade, the Department of Mines and Petroleum (DMP) has been mapping closed and abandoned mine sites. They now have a database that includes about 17,000 sites.

Many of these sites are relatively small and include shallow scrapings or stockpiles.

However, there are also a number of old shafts with equipment that may not be safe.

Hard Rock (featured in the above video) has been mining underground for around thirty years.

One of the mine sites he worked at was called Noble's Nob, near Tenant Creek.

In 1967, Hard Rock was working underground when the ground started to fall in.

"I was running my guts out to reach the top!" says Hard Rock of the harrowing experience.

He recalls dust and earth falling quickly behind him. It was a very narrow escape that he managed to get out of the shaft at all.

The collapse engulfed a lot of the mine's equipment which resulted in the development of open cut mining, which is still the preferred method for most large mining operations today.

Hard Rock says all abandoned mines should be filled in. However, this is often a costly exercise and, in some cases, the abandoned mine can still be under lease. This means that the owners of the lease can leave the mine and come back to it at a later date.

Old abandoned mine sites can be very interesting, due to their heritage and educational value, but it’s also important to have some understanding of the dangers that may be lying around.

DMP Environment Division Executive Director, Dr Phil Gorey, says: "People need to take care when traveling in Western Australia and be aware that abandoned mine sites can present a hazard."

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Comments

Curtis Jones

@GMS_Grandmaster_V
It's a question of both rock / soil chemistry and of the chemistry of the underlying water table. Many mined commodities are hosted in mineralised ground that contains appreciable amounts of sulphides, carbonates & oxides that on contact with water, oxygen and other substances will leach out of the host material and / or chemically alter. A simplified example - high exposed sulphide mineralisation plus high rainfall often results in Acid Mine Drainage. AMD is undesirable, as it presents an unviable environment for aquatic flora and fauna with subsequent effects on land. Google "Acid Mine Drainage" for more information but make sure you steer clear of the more hysterical websites - they would have you think that all mining causes acid drainage impact no matter what, which is incorrect. The ground water chemistry is also important. For example, the eastern goldfields of WA in a belt from roughly Menzies down to Norseman has groundwater which is hypersaline and contains large quantities of dissolved solids such as gypsum, and is encountered at relatively shallow depths. Most open pits in the eastern goldfields will, on abandonment, recharge with ground water, which cannot be used for any consumption or agricultural purposes, due to the high solute content. The water in old pits in that area is often an attractive looking blue or green but don't be fooled, this is often due to high solute levels of cobalt, copper or other metals. You will see the odd pit that contains nice fresh water - they are usually muddy in color like any other station dam - there is a ripper near Broad Arrow called Bulletin that is popular on weekends. You can occasionally see some weird things where fresh water from rainfall and hypersaline ground water stratify in old pits - Queen Lapage on Lake Yindarlgooda is one - objects will float at the fresh/saline boundary. Go a little further north though to Menzies and the ground water is pretty good, suitable for stock and drinkable in a pinch. TLDR; - most old pits are unsuitable for storage of water for agriculture or consumption.

Curtis Jones

Interesting piece. Not entirely sure what it is you're attempting to say with it though. Has there been a spate of incidents related to inexperienced people entering workings?
Simply 'filling them in' might sound good. People from the coast, from the cities, when confronted with a large open pit mine often say something similar - "It should be filled in!" - but beyond a vague mumbling around environment are unable to provide a compelling reason to do so. There is no good reason to 'fill in' old mines, be they open pit or underground workings. There is the obvious question of cost, but even more so there are an uncounted multitude of examples where old underground mines and open pit mines are successfully returned to profitable production due to changes in commodity pricing, sometimes quite a few decades since mining ceased. No, 'filling them in' is no option at all.
There is however compelling reasons to make them as safe as possible on abandonment. Current practices are reasonable, workings are surrounded by an abandonment bund, roads removed, ripped, reseeded, infrastructure removed and the area in general is rehabilitated. More can be done, I believe, with regards to a standardised approach to signage for abandoned workings.
But the problem is not so much newer workings but older ones, and there the problem is - who's responsible? In many of these cases, workings may be a number of decades old, the original developers long since gone, the leases reverted back to the state. Should the state then bear the costs of rehabilitation and making them safe? Perhaps the shires in which old workings exist should cover it? Or should it be the responsibility of pastoral lease holders?
The practical answer is, it is almost entirely the mining industry that rehabilitates and makes safe old workings. This occurs when a modern mining operation is established over an older one, reactivating it, extracting further mineral wealth and on completion properly rehabilitating it. It's not just the province of the larger mining companies either, a number of Golden Gecko awards have been presented by the DoMP in WA to prospectors for their efforts in rehabilitation and making safe of old workings.
There is little incentive however for the mining industry at large to seek out old workings that exist on it's leases and invest money in rehabilitating them and making them safe purely for the sake of doing so.
Several things could be done to help change this.
Firstly, clear guidelines and guidance on requirements for successfully rehabilitating and making safe old workings. This is something that the DoMP and industry could easily thrash out and agree on - we excel at using that approach for other concerns. Standards for bunding, for fencing, for signage, for clearing, for ripping, reseeding, contouring, all of it.
Secondly, define an appropriate incentive for mining companies to engage in rehabilitation and making safe old workings that exist on their leases. This could take the form of a reduction on bonds related to current mining operations. It could take the form of a credit that could be applied to lease expenditure on other leases that a given entity owns. It could take the form of a percentage reduction in royalties paid to the state. There are any number of possible ways that the expenditure incurred to rehabilitate and make safe old workings would become worthwhile.
Lastly, legislate it and lock it in.
Appropriately empower the mining industry in WA to fix the issue and it will be fixed. No other approach will work.

GMS_GrandMaster_V

If the soil is no toxic you can use them as large fresh water reservoirs.

Bruce Crunkhorn

During the 1970's I worked as an airleg miner and jumbo operator as either a development miner or production miner in hardrock mines around Australia.
I believe access to old mines should be secured to prevent access not because of possible rock fall or similar hazards but because people entering old drives or declines may unknowingly encounter areas where there is limited oxygen. This occurs where there is organic matter such as old timbers or sleepers lying in water decomposing thus reducing the oxygen. People may be overcome by carbon dioxide and collapse without being aware of what is happening. There is a whole industry about safety and entry to confined spaces.
Entrances to shafts, drives and declines should be secured though "filling in " is not a practical option

Beth Neate

Hard Rock, as someone who gets claustrophobic I admit your story of the earth falling behind you is one of my worst nightmares. I'll be keeping well away.